The LCD (Liquid Crystal Display) possesses advantages of thin body, power saving and no radiation to be widely used in many application scope. It has been widely utilized in, such as mobile phones, PDAs (personal digital assistance), digital cameras, laptop screens or notebook screens.
The present thin film transistor liquid crystal display comprises a shell, a LCD panel located in the shell and a backlight module located in the shell. The structure of the liquid crystal display panel mainly comprises a Thin Film Transistor Array Substrate (TFT Array Substrate), a Color Filter (CF) and a Liquid Crystal Layer arranged between the two substrates. Generally, the thin film transistor array substrate comprises scan lines, data lines, thin film transistors and pixel electrodes; the color filter substrate comprises a black matrix, color filters and a common electrode. The working procedure of the liquid crystal display panel is: the scan drive signal is inputted to the scan line, and the TFT coupled to the scan line is conducted, and the data signal loaded by the data line is applied to the pixel electrode through the TFT. The rotations of the liquid crystal molecules are controlled with the electrical field formed between the pixel electrode and the common electrode. The rotated liquid crystal molecules refract the light of the backlight module and the light passes through the color filters to show color images.
The color filters are the key component of the liquid crystal display to achieve colorization. The function principle is to utilize the light filtering way to generate three primary colors, red (R), green (G), blue (B). Then, the three primary colors are mixed with various ratios to generate respective colors for making the liquid crystal display panel show colors. The performance of the CF substrate (the color purity, the aperture ratio, the chromatism) directly affects the abilities of the color saturation, color contrast ratio, display brightness.
Please refer to FIG. 1, which is a sectional structure diagram of a color filter substrate according to prior art, comprising a substrate 100 and a color filter layer 110 positioned on the substrate 100. The color filter layer 110 comprises red filters R, green filters G, blue filters B aligned in matrix. The red filters R, the green filters G, the blue filters B are manufactured by pigment dispersion. A black matrix 310 separates the respective color filters. At present, it remains facing challenge to satisfy liquid crystal displays of different demands, such as the high brightness liquid crystal display for outdoor display and the high color saturation liquid crystal display. One important reason is that the present color filter substrate cannot satisfy the demands of the high brightness and the high color saturation at the same time. Although there already has a method of adding white (W) matrix to obtain the RGBW display matrix for acquiring the high brightness liquid crystal display device, the color saturation will be weakened as increasing the brightness. The demands of the high brightness and the high color saturation cannot be satisfied at the same time.
The electrochromism means the phenomenon that the absorption wavelength if the material generates the reversible change with the function of the external electric field, which actually is an electrochemistry oxidation-reduction reaction. The material shows the reversible change of the color in appearance after reaction. The electrochromic material can appear to be transparent without any colors in condition of no electric field. Then, as the electric field is applied through the external source, the electrochromic material can show a specific color; or it can show the specific color in condition of no electric field, and as the electric field is applied, the electrochromic material appears to be transparent without any colors. Meanwhile, the electrochromic material has memory function. When the external electric field disappears, the color can remain unchanged. The electrochromic device utilizing the electrochromic phenomenon has kinds of advantages, such as having the high reflectivity but without external light source, and possessing the merits of high contrast ratio, low driving voltage and rich colors. It provides excellent flexibility and portability, and reduces weight. Therefore, the electrochromic material possesses a certain potential to be applied in the display device field and draws tons of attention.